/*
100% free public domain implementation of the SHA-1 algorithm
by Dominik Reichl <dominik.reichl@t-online.de>
Web: http://www.dominik-reichl.de/

Version 1.6 - 2005-02-07 (thanks to Howard Kapustein for patches)
- You can set the endianness in your files, no need to modify the
header file of the CSHA1 class any more
- Aligned data support
- Made support/compilation of the utility functions (ReportHash
and HashFile) optional (useful, if bytes count, for example in
embedded environments)

Version 1.5 - 2005-01-01
- 64-bit compiler compatibility added
- Made variable wiping optional (define SHA1_WIPE_VARIABLES)
- Removed unnecessary variable initializations
- ROL32 improvement for the Microsoft compiler (using _rotl)

======== Test Vectors (from FIPS PUB 180-1) ========

SHA1("abc") =
A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D

SHA1("abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq") =
84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1

SHA1(A million repetitions of "a") =
34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
*/

#include "SHA1.h"

#ifdef SHA1_UTILITY_FUNCTIONS
#define SHA1_MAX_FILE_BUFFER 8000
#endif

// Rotate x bits to the left
#ifndef ROL32
#ifdef _MSC_VER
#define ROL32(_val32, _nBits) _rotl(_val32, _nBits)
#else
#define ROL32(_val32, _nBits) (((_val32)<<(_nBits))|((_val32)>>(32-(_nBits))))
#endif
#endif

#ifdef SHA1_LITTLE_ENDIAN
#define SHABLK0(i) (m_block->l[i] = \
  (ROL32(m_block->l[i],24) & 0xFF00FF00) | (ROL32(m_block->l[i],8) & 0x00FF00FF))
#else
#define SHABLK0(i) (m_block->l[i])
#endif

#define SHABLK(i) (m_block->l[i&15] = ROL32(m_block->l[(i+13)&15] ^ m_block->l[(i+8)&15] \
  ^ m_block->l[(i+2)&15] ^ m_block->l[i&15],1))

// SHA-1 rounds
#define _R0(v,w,x,y,z,i) { z+=((w&(x^y))^y)+SHABLK0(i)+0x5A827999+ROL32(v,5); w=ROL32(w,30); }
#define _R1(v,w,x,y,z,i) { z+=((w&(x^y))^y)+SHABLK(i)+0x5A827999+ROL32(v,5); w=ROL32(w,30); }
#define _R2(v,w,x,y,z,i) { z+=(w^x^y)+SHABLK(i)+0x6ED9EBA1+ROL32(v,5); w=ROL32(w,30); }
#define _R3(v,w,x,y,z,i) { z+=(((w|x)&y)|(w&x))+SHABLK(i)+0x8F1BBCDC+ROL32(v,5); w=ROL32(w,30); }
#define _R4(v,w,x,y,z,i) { z+=(w^x^y)+SHABLK(i)+0xCA62C1D6+ROL32(v,5); w=ROL32(w,30); }

CSHA1::CSHA1()
{
  m_block = (SHA1_WORKSPACE_BLOCK *)m_workspace;

  Reset();
}

CSHA1::~CSHA1()
{
  Reset();
}

void CSHA1::Reset()
{
  // SHA1 initialization constants
  m_state[0] = 0x67452301;
  m_state[1] = 0xEFCDAB89;
  m_state[2] = 0x98BADCFE;
  m_state[3] = 0x10325476;
  m_state[4] = 0xC3D2E1F0;

  m_count[0] = 0;
  m_count[1] = 0;
}

void CSHA1::Transform(UINT_32 *state, UINT_8 *buffer)
{
  // Copy state[] to working vars
  UINT_32 a = state[0], b = state[1], c = state[2], d = state[3], e = state[4];

  memcpy(m_block, buffer, 64);

  // 4 rounds of 20 operations each. Loop unrolled.
  _R0(a,b,c,d,e, 0); _R0(e,a,b,c,d, 1); _R0(d,e,a,b,c, 2); _R0(c,d,e,a,b, 3);
  _R0(b,c,d,e,a, 4); _R0(a,b,c,d,e, 5); _R0(e,a,b,c,d, 6); _R0(d,e,a,b,c, 7);
  _R0(c,d,e,a,b, 8); _R0(b,c,d,e,a, 9); _R0(a,b,c,d,e,10); _R0(e,a,b,c,d,11);
  _R0(d,e,a,b,c,12); _R0(c,d,e,a,b,13); _R0(b,c,d,e,a,14); _R0(a,b,c,d,e,15);
  _R1(e,a,b,c,d,16); _R1(d,e,a,b,c,17); _R1(c,d,e,a,b,18); _R1(b,c,d,e,a,19);
  _R2(a,b,c,d,e,20); _R2(e,a,b,c,d,21); _R2(d,e,a,b,c,22); _R2(c,d,e,a,b,23);
  _R2(b,c,d,e,a,24); _R2(a,b,c,d,e,25); _R2(e,a,b,c,d,26); _R2(d,e,a,b,c,27);
  _R2(c,d,e,a,b,28); _R2(b,c,d,e,a,29); _R2(a,b,c,d,e,30); _R2(e,a,b,c,d,31);
  _R2(d,e,a,b,c,32); _R2(c,d,e,a,b,33); _R2(b,c,d,e,a,34); _R2(a,b,c,d,e,35);
  _R2(e,a,b,c,d,36); _R2(d,e,a,b,c,37); _R2(c,d,e,a,b,38); _R2(b,c,d,e,a,39);
  _R3(a,b,c,d,e,40); _R3(e,a,b,c,d,41); _R3(d,e,a,b,c,42); _R3(c,d,e,a,b,43);
  _R3(b,c,d,e,a,44); _R3(a,b,c,d,e,45); _R3(e,a,b,c,d,46); _R3(d,e,a,b,c,47);
  _R3(c,d,e,a,b,48); _R3(b,c,d,e,a,49); _R3(a,b,c,d,e,50); _R3(e,a,b,c,d,51);
  _R3(d,e,a,b,c,52); _R3(c,d,e,a,b,53); _R3(b,c,d,e,a,54); _R3(a,b,c,d,e,55);
  _R3(e,a,b,c,d,56); _R3(d,e,a,b,c,57); _R3(c,d,e,a,b,58); _R3(b,c,d,e,a,59);
  _R4(a,b,c,d,e,60); _R4(e,a,b,c,d,61); _R4(d,e,a,b,c,62); _R4(c,d,e,a,b,63);
  _R4(b,c,d,e,a,64); _R4(a,b,c,d,e,65); _R4(e,a,b,c,d,66); _R4(d,e,a,b,c,67);
  _R4(c,d,e,a,b,68); _R4(b,c,d,e,a,69); _R4(a,b,c,d,e,70); _R4(e,a,b,c,d,71);
  _R4(d,e,a,b,c,72); _R4(c,d,e,a,b,73); _R4(b,c,d,e,a,74); _R4(a,b,c,d,e,75);
  _R4(e,a,b,c,d,76); _R4(d,e,a,b,c,77); _R4(c,d,e,a,b,78); _R4(b,c,d,e,a,79);

  // Add the working vars back into state
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;

  // Wipe variables
#ifdef SHA1_WIPE_VARIABLES
  a = b = c = d = e = 0;
#endif
}

// Use this function to hash in binary data and strings
void CSHA1::Update(UINT_8 *data, UINT_32 len)
{
  UINT_32 i, j;

  j = (m_count[0] >> 3) & 63;

  if((m_count[0] += len << 3) < (len << 3)) m_count[1]++;

  m_count[1] += (len >> 29);

  if((j + len) > 63)
  {
    i = 64 - j;
    memcpy(&m_buffer[j], data, i);
    Transform(m_state, m_buffer);

    for(; i + 63 < len; i += 64) Transform(m_state, &data[i]);

    j = 0;
  }
  else i = 0;

  memcpy(&m_buffer[j], &data[i], len - i);
}

#ifdef SHA1_UTILITY_FUNCTIONS
// Hash in file contents
bool CSHA1::HashFile(char *szFileName)
{
  unsigned long ulFileSize, ulRest, ulBlocks;
  unsigned long i;
  UINT_8 uData[SHA1_MAX_FILE_BUFFER];
  FILE *fIn;

  if(szFileName == NULL) return false;

  fIn = fopen(szFileName, "rb");
  if(fIn == NULL) return false;

  fseek(fIn, 0, SEEK_END);
  ulFileSize = (unsigned long)ftell(fIn);
  fseek(fIn, 0, SEEK_SET);

  if(ulFileSize != 0)
  {
    ulBlocks = ulFileSize / SHA1_MAX_FILE_BUFFER;
    ulRest = ulFileSize % SHA1_MAX_FILE_BUFFER;
  }
  else
  {
    ulBlocks = 0;
    ulRest = 0;
  }

  for(i = 0; i < ulBlocks; i++)
  {
    fread(uData, 1, SHA1_MAX_FILE_BUFFER, fIn);
    Update((UINT_8 *)uData, SHA1_MAX_FILE_BUFFER);
  }

  if(ulRest != 0)
  {
    fread(uData, 1, ulRest, fIn);
    Update((UINT_8 *)uData, ulRest);
  }

  fclose(fIn); fIn = NULL;
  return true;
}
#endif

void CSHA1::Final()
{
  UINT_32 i;
  UINT_8 finalcount[8];

  for(i = 0; i < 8; i++)
    finalcount[i] = (UINT_8)((m_count[((i >= 4) ? 0 : 1)]
  >> ((3 - (i & 3)) * 8) ) & 255); // Endian independent

  Update((UINT_8 *)"\200", 1);

  while ((m_count[0] & 504) != 448)
    Update((UINT_8 *)"\0", 1);

  Update(finalcount, 8); // Cause a SHA1Transform()

  for(i = 0; i < 20; i++)
  {
    m_digest[i] = (UINT_8)((m_state[i >> 2] >> ((3 - (i & 3)) * 8) ) & 255);
  }

  // Wipe variables for security reasons
#ifdef SHA1_WIPE_VARIABLES
  i = 0;
  memset(m_buffer, 0, 64);
  memset(m_state, 0, 20);
  memset(m_count, 0, 8);
  memset(finalcount, 0, 8);
  Transform(m_state, m_buffer);
#endif
}

#ifdef SHA1_UTILITY_FUNCTIONS
// Get the final hash as a pre-formatted string
void CSHA1::ReportHash(char *szReport, unsigned char uReportType)
{
  unsigned char i;
  char szTemp[16];

  if(szReport == NULL) return;

  if(uReportType == REPORT_HEX)
  {
    sprintf(szTemp, "%02X", m_digest[0]);
    strcat(szReport, szTemp);

    for(i = 1; i < 20; i++)
    {
      sprintf(szTemp, " %02X", m_digest[i]);
      strcat(szReport, szTemp);
    }
  }
  else if(uReportType == REPORT_DIGIT)
  {
    sprintf(szTemp, "%u", m_digest[0]);
    strcat(szReport, szTemp);

    for(i = 1; i < 20; i++)
    {
      sprintf(szTemp, " %u", m_digest[i]);
      strcat(szReport, szTemp);
    }
  }
  else strcpy(szReport, "Error: Unknown report type!");
}
#endif

// Get the raw message digest
void CSHA1::GetHash(UINT_8 *puDest)
{
  memcpy(puDest, m_digest, 20);
}
